• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1195-1198
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• 2013

Nickel hexacyanoferrate supported palladium nanoparticles (Pd-NiHCF NPs) were synthesized and studied for oxygen reduction reactions in direct methanol fuel cell. The NiHCF support was readily synthesized by a comixing of $Ni(OCOCH_3)_2$ and equimolar $K_3[Fe(CN)_6]$ solution into DI water under rigorous stirring. After the preparation of NiHCF support, Pd NPs were loaded on NiHCF via L-ascorbic acid reduction method at $80^{\circ}C$. Pd-NiHCF NPs were electrochemically active for oxygen reduction reaction in 0.1 M $HClO_4$ solution. X-ray absorption near edge structure analysis was conducted to measure the white line intensity of Pd-NiHCF to verify the OH adsorption. As a comparison, carbon supported Pd NPs exhibited same white line intensity. This study provides a general synthetic approach to easily load Pd NPs on porous coordination polymers such as NiHCF and can provide further light to load Pd based alloy NPs on NiHCF framework.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.208-208
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• 2013

Graphene has emerged as a fascinating material for next-generation nanoelectronics due to its outstanding electronic properties. In particular, graphene-based field effect transistors (GFETs) have been a promising research subject due to their superior response times, which are due to extremely high electron mobility at room temperature. The biggest challenges in GFET applications are control of carrier concentration and opening the bandgap of graphene. To overcome these problems, three approaches to doping graphene have been developed. Here we demonstrate the decoration of Ni nanoparticles (NPs) on graphene films by simple annealing for p-type doping of graphene. Ni NPs/graphene films were fabricated by coating a $NiCl2{\cdot}6H2O$ solution onto graphene followedby annealing. Scanning electron microscopy and atomic force microscopy revealed that high-density, uniformly sized Ni NPs were formed on the graphene films and the density of the Ni NPs increased gradually with increasing $NiCl2{\cdot}6H2O$ concentration. The formation of Ni NPs on graphene films was explained by heat-driven dechlorination and subsequent particlization, as investigated by X-ray photoelectron spectroscopy. The doping effect of Ni NPs onto graphene films was verified by Raman spectroscopy and electrical transport measurements.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 춘계학술강연 및 발표대회강연 및 발표논문 초록집
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• pp.59-60
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• 2006

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2005년도 추계학술강연 및 발표대회강연 및 발표논문 초록집
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• pp.61-62
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• 2005

• 한국결정성장학회지
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• 제22권5호
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• pp.218-222
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• 2012

FeNi alloy nanofibers have been prepared by an electrospinning process followed by air-calcination and H2 reduction to develop electromagnetic (EM) wave absorbers in the giga-hertz (GHz) frequency range. The thermal behavior and phase and morphology evolution in the synthetic processes were systematically investigated. Through the heat treatments of calcination and H2 reduction, as-spun PVP/FeNi precursor nanofiber has been stepwise transformed into nickel iron oxide and FeNi phases but the fibrous shape was maintained perfectly. The FeNi alloy nanofiber had the high aspect ratio and the average diameter of approximately 190 nm and primarily composed of FeNi nanocrystals with an average diameter of ~60 nm. The FeNi alloy nanofibers could be used for excellent EM wave absorbing materials in the GHz frequency range because the power loss of the FeNi nanofibers increased up to 20 GHz without a degradation and exhibited the superior EM wave absorption properties compared to commercial FeNi nanoparticles.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2003년도 international symposium on advanced powder metallurgy
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• pp.101-102
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• 2003

• 한국재료학회지
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• 제31권9호
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• pp.525-531
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• 2021

Carbon-encapsulated Ni catalysts are synthesized by an electrical explosion of wires (EEW) method and applied for CO₂ methanation. We find that the presence of carbon shell on Ni nanoparticles as catalyst can positively affect CO₂ methanation reaction. Ni@5C that is produced under 5 % CH₄ partial pressure in Ar gas has highest conversions of 68 % at 350 ℃ and 70 % at 400 ℃, which are 73 and 75 % of the thermodynamic equilibrium conversion, respectively. The catalyst of Ni@10C with thicker carbon layer shows much reduced activity. The EEW-produced Ni catalysts with low specific surface area outperform Ni catalysts with high surface area synthesized by solution-based precipitation methods. Our finding in this study shows the possibility of utilizing carbon-encapsulated metal catalysts for heterogeneous catalysis reaction including CO₂ methanation. Furthermore, EEW, which is a highly promising method for massive production of metal nanoparticles, can be applied for various catalysis system, requiring scaled-up synthesis of catalysts.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2584-2592
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• 2011

Nickel nanoparticle-poly(N-vinyl-2-pyrrolidone)/$TiO_2-ZrO_2$ composite (Ni-PVP/$TiO_2-ZrO_2$) was prepared by in situ polymerization method. The physical and chemical properties of Ni-PVP/$TiO_2-ZrO_2$ were investigated by XRD, FT-IR, BET, TGA, SEM and TEM techniques. The catalytic performance of this novel heterogeneous catalyst was determined for the Suzuki-Miyaura cross-coupling reaction between aryl halides and phenylboronic acid in the presence of methanol-water mixture as solvent. The effects of reaction temperature, the amount of catalyst, amount of support, solvent, and amount of metal for the synthesis of Ni-PVP/$TiO_2-ZrO_2$, were investigated as well as recyclability of the heterogeneous composite. The catalyst used for this synthetically useful transformation showed considerable level of reusability besides very good activity.

• 청정기술
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• 제28권2호
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• pp.154-162
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• 2022

알루미늄 (Al) 금속을 전구체 및 구조체로 이용, 수열 반응을 통하여 Al@Al₂O₃와 Al@Ni-Al LDH (LDH = layered double hydroxide) 코어-쉘 복합 구조체를 합성하였다. 제조된 구조체의 형상, 조성, 결정 구조는 수용액에 존재하는 이온들에 의하여 크게 영향을 받았으며, 이를 활용하여 다양한 특성의 촉매 구조체 유도가 가능하였다. Al@Ni-Al LDH 코어-쉘 구조체의 환원을 통하여 Ni 나노 입자가 고정화된 Ni/Al@Al₂O₃ 촉매를 제조하였고, CO₂ 메탄화 반응에 적용하여 촉매의 특성을 평가하였다. Ni/Al@Al₂O₃ 촉매는 전통적 incipient wetness impregnation 방법에 의하여 제조된 Ni/Al₂O₃ 촉매에 비교하여 Ni 입자의 분산도와 균일성이 매우 높았으며 약 2 배 이상의 CO₂ 전환율로 높은 촉매적 활성과 더불어 구조의 안정성을 보여 주었다. 이러한 Ni/Al@Al₂O₃ 구조체 촉매의 우수한 특성은 Al 금속을 기반으로 한 새로운 개념의 촉매 구조체 설계와 합성 방법의 타당성을 보여준다.

• Korean Chemical Engineering Research
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• 제49권6호
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• pp.846-850
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• 2011

주석과 니켈 나노입자를 함량별로 혼합하여 습식법으로 리튬 이차전지용 복합체 음전극을 제조하고 그 물성과 전기화학적 특성을 조사하였다. 이 음전극은 초기 방전시 최대 700 mAh $g^{-1}$의 우수한 방전용량을 나타내었지만 사이클 특성은 심각한 열화를 보였다. 이것은 나노입자간 단순혼합만으로는 전극판의 기공성과 Ni 성분이 충방전에 따르는 Sn성분의 팽창/수축에 대한 기계적 완충제 역할이 충분하지 않았기 때문이며, 차후 이를 보완하는 나노구조체 Sn-Ni 음전극의 설계와 시험이 필요하다.